1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
|
import numpy as np
import scipy.sparse as sp
from sklearn.utils.testing import assert_array_almost_equal
from sklearn.utils.testing import assert_almost_equal
from sklearn.utils.testing import assert_equal
from sklearn.utils.testing import assert_less
from sklearn.utils.testing import assert_greater
from sklearn.utils.testing import ignore_warnings
from sklearn.linear_model.coordinate_descent import (Lasso, ElasticNet,
LassoCV, ElasticNetCV)
def test_sparse_coef():
# Check that the sparse_coef property works
clf = ElasticNet()
clf.coef_ = [1, 2, 3]
assert sp.isspmatrix(clf.sparse_coef_)
assert_equal(clf.sparse_coef_.toarray().tolist()[0], clf.coef_)
def test_normalize_option():
# Check that the normalize option in enet works
X = sp.csc_matrix([[-1], [0], [1]])
y = [-1, 0, 1]
clf_dense = ElasticNet(fit_intercept=True, normalize=True)
clf_sparse = ElasticNet(fit_intercept=True, normalize=True)
clf_dense.fit(X, y)
X = sp.csc_matrix(X)
clf_sparse.fit(X, y)
assert_almost_equal(clf_dense.dual_gap_, 0)
assert_array_almost_equal(clf_dense.coef_, clf_sparse.coef_)
def test_lasso_zero():
# Check that the sparse lasso can handle zero data without crashing
X = sp.csc_matrix((3, 1))
y = [0, 0, 0]
T = np.array([[1], [2], [3]])
clf = Lasso().fit(X, y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0])
assert_array_almost_equal(pred, [0, 0, 0])
assert_almost_equal(clf.dual_gap_, 0)
def test_enet_toy_list_input():
# Test ElasticNet for various values of alpha and l1_ratio with list X
X = np.array([[-1], [0], [1]])
X = sp.csc_matrix(X)
Y = [-1, 0, 1] # just a straight line
T = np.array([[2], [3], [4]]) # test sample
# this should be the same as unregularized least squares
clf = ElasticNet(alpha=0, l1_ratio=1.0)
# catch warning about alpha=0.
# this is discouraged but should work.
ignore_warnings(clf.fit)(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [1])
assert_array_almost_equal(pred, [2, 3, 4])
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.3, max_iter=1000)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.50819], decimal=3)
assert_array_almost_equal(pred, [1.0163, 1.5245, 2.0327], decimal=3)
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.5)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.45454], 3)
assert_array_almost_equal(pred, [0.9090, 1.3636, 1.8181], 3)
assert_almost_equal(clf.dual_gap_, 0)
def test_enet_toy_explicit_sparse_input():
# Test ElasticNet for various values of alpha and l1_ratio with sparse X
f = ignore_warnings
# training samples
X = sp.lil_matrix((3, 1))
X[0, 0] = -1
# X[1, 0] = 0
X[2, 0] = 1
Y = [-1, 0, 1] # just a straight line (the identity function)
# test samples
T = sp.lil_matrix((3, 1))
T[0, 0] = 2
T[1, 0] = 3
T[2, 0] = 4
# this should be the same as lasso
clf = ElasticNet(alpha=0, l1_ratio=1.0)
f(clf.fit)(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [1])
assert_array_almost_equal(pred, [2, 3, 4])
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.3, max_iter=1000)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.50819], decimal=3)
assert_array_almost_equal(pred, [1.0163, 1.5245, 2.0327], decimal=3)
assert_almost_equal(clf.dual_gap_, 0)
clf = ElasticNet(alpha=0.5, l1_ratio=0.5)
clf.fit(X, Y)
pred = clf.predict(T)
assert_array_almost_equal(clf.coef_, [0.45454], 3)
assert_array_almost_equal(pred, [0.9090, 1.3636, 1.8181], 3)
assert_almost_equal(clf.dual_gap_, 0)
def make_sparse_data(n_samples=100, n_features=100, n_informative=10, seed=42,
positive=False, n_targets=1):
random_state = np.random.RandomState(seed)
# build an ill-posed linear regression problem with many noisy features and
# comparatively few samples
# generate a ground truth model
w = random_state.randn(n_features, n_targets)
w[n_informative:] = 0.0 # only the top features are impacting the model
if positive:
w = np.abs(w)
X = random_state.randn(n_samples, n_features)
rnd = random_state.uniform(size=(n_samples, n_features))
X[rnd > 0.5] = 0.0 # 50% of zeros in input signal
# generate training ground truth labels
y = np.dot(X, w)
X = sp.csc_matrix(X)
if n_targets == 1:
y = np.ravel(y)
return X, y
def _test_sparse_enet_not_as_toy_dataset(alpha, fit_intercept, positive):
n_samples, n_features, max_iter = 100, 100, 1000
n_informative = 10
X, y = make_sparse_data(n_samples, n_features, n_informative,
positive=positive)
X_train, X_test = X[n_samples // 2:], X[:n_samples // 2]
y_train, y_test = y[n_samples // 2:], y[:n_samples // 2]
s_clf = ElasticNet(alpha=alpha, l1_ratio=0.8, fit_intercept=fit_intercept,
max_iter=max_iter, tol=1e-7, positive=positive,
warm_start=True)
s_clf.fit(X_train, y_train)
assert_almost_equal(s_clf.dual_gap_, 0, 4)
assert_greater(s_clf.score(X_test, y_test), 0.85)
# check the convergence is the same as the dense version
d_clf = ElasticNet(alpha=alpha, l1_ratio=0.8, fit_intercept=fit_intercept,
max_iter=max_iter, tol=1e-7, positive=positive,
warm_start=True)
d_clf.fit(X_train.toarray(), y_train)
assert_almost_equal(d_clf.dual_gap_, 0, 4)
assert_greater(d_clf.score(X_test, y_test), 0.85)
assert_almost_equal(s_clf.coef_, d_clf.coef_, 5)
assert_almost_equal(s_clf.intercept_, d_clf.intercept_, 5)
# check that the coefs are sparse
assert_less(np.sum(s_clf.coef_ != 0.0), 2 * n_informative)
def test_sparse_enet_not_as_toy_dataset():
_test_sparse_enet_not_as_toy_dataset(alpha=0.1, fit_intercept=False,
positive=False)
_test_sparse_enet_not_as_toy_dataset(alpha=0.1, fit_intercept=True,
positive=False)
_test_sparse_enet_not_as_toy_dataset(alpha=1e-3, fit_intercept=False,
positive=True)
_test_sparse_enet_not_as_toy_dataset(alpha=1e-3, fit_intercept=True,
positive=True)
def test_sparse_lasso_not_as_toy_dataset():
n_samples = 100
max_iter = 1000
n_informative = 10
X, y = make_sparse_data(n_samples=n_samples, n_informative=n_informative)
X_train, X_test = X[n_samples // 2:], X[:n_samples // 2]
y_train, y_test = y[n_samples // 2:], y[:n_samples // 2]
s_clf = Lasso(alpha=0.1, fit_intercept=False, max_iter=max_iter, tol=1e-7)
s_clf.fit(X_train, y_train)
assert_almost_equal(s_clf.dual_gap_, 0, 4)
assert_greater(s_clf.score(X_test, y_test), 0.85)
# check the convergence is the same as the dense version
d_clf = Lasso(alpha=0.1, fit_intercept=False, max_iter=max_iter, tol=1e-7)
d_clf.fit(X_train.toarray(), y_train)
assert_almost_equal(d_clf.dual_gap_, 0, 4)
assert_greater(d_clf.score(X_test, y_test), 0.85)
# check that the coefs are sparse
assert_equal(np.sum(s_clf.coef_ != 0.0), n_informative)
def test_enet_multitarget():
n_targets = 3
X, y = make_sparse_data(n_targets=n_targets)
estimator = ElasticNet(alpha=0.01, fit_intercept=True, precompute=None)
# XXX: There is a bug when precompute is not None!
estimator.fit(X, y)
coef, intercept, dual_gap = (estimator.coef_,
estimator.intercept_,
estimator.dual_gap_)
for k in range(n_targets):
estimator.fit(X, y[:, k])
assert_array_almost_equal(coef[k, :], estimator.coef_)
assert_array_almost_equal(intercept[k], estimator.intercept_)
assert_array_almost_equal(dual_gap[k], estimator.dual_gap_)
def test_path_parameters():
X, y = make_sparse_data()
max_iter = 50
n_alphas = 10
clf = ElasticNetCV(n_alphas=n_alphas, eps=1e-3, max_iter=max_iter,
l1_ratio=0.5, fit_intercept=False)
ignore_warnings(clf.fit)(X, y) # new params
assert_almost_equal(0.5, clf.l1_ratio)
assert_equal(n_alphas, clf.n_alphas)
assert_equal(n_alphas, len(clf.alphas_))
sparse_mse_path = clf.mse_path_
ignore_warnings(clf.fit)(X.toarray(), y) # compare with dense data
assert_almost_equal(clf.mse_path_, sparse_mse_path)
def test_same_output_sparse_dense_lasso_and_enet_cv():
X, y = make_sparse_data(n_samples=40, n_features=10)
for normalize in [True, False]:
clfs = ElasticNetCV(max_iter=100, cv=5, normalize=normalize)
ignore_warnings(clfs.fit)(X, y)
clfd = ElasticNetCV(max_iter=100, cv=5, normalize=normalize)
ignore_warnings(clfd.fit)(X.toarray(), y)
assert_almost_equal(clfs.alpha_, clfd.alpha_, 7)
assert_almost_equal(clfs.intercept_, clfd.intercept_, 7)
assert_array_almost_equal(clfs.mse_path_, clfd.mse_path_)
assert_array_almost_equal(clfs.alphas_, clfd.alphas_)
clfs = LassoCV(max_iter=100, cv=4, normalize=normalize)
ignore_warnings(clfs.fit)(X, y)
clfd = LassoCV(max_iter=100, cv=4, normalize=normalize)
ignore_warnings(clfd.fit)(X.toarray(), y)
assert_almost_equal(clfs.alpha_, clfd.alpha_, 7)
assert_almost_equal(clfs.intercept_, clfd.intercept_, 7)
assert_array_almost_equal(clfs.mse_path_, clfd.mse_path_)
assert_array_almost_equal(clfs.alphas_, clfd.alphas_)
def test_same_multiple_output_sparse_dense():
for normalize in [True, False]:
l = ElasticNet(normalize=normalize)
X = [[0, 1, 2, 3, 4],
[0, 2, 5, 8, 11],
[9, 10, 11, 12, 13],
[10, 11, 12, 13, 14]]
y = [[1, 2, 3, 4, 5],
[1, 3, 6, 9, 12],
[10, 11, 12, 13, 14],
[11, 12, 13, 14, 15]]
ignore_warnings(l.fit)(X, y)
sample = np.array([1, 2, 3, 4, 5]).reshape(1, -1)
predict_dense = l.predict(sample)
l_sp = ElasticNet(normalize=normalize)
X_sp = sp.coo_matrix(X)
ignore_warnings(l_sp.fit)(X_sp, y)
sample_sparse = sp.coo_matrix(sample)
predict_sparse = l_sp.predict(sample_sparse)
assert_array_almost_equal(predict_sparse, predict_dense)
|
